1. Field of the Invention
The present invention relates to a video-processing chip, and more particularly, to a video-processing chip with a memory storing program codes for controlling a power switch.
2. Description of the Prior Art
Digital Versatile Disc (DVD) players have become the most popular electronic audio-video apparatus today. Due to vigorous developments and lower prices of all kinds of display panels, portable audio-video apparatus get more and more popular. Hence, power consumption becomes an important condition design consideration for the portable audio-video apparatus.
Please refer to FIG. 1. FIG. 1 is a diagram of an audio-video system 10 according to the prior art. The audio-video system 10 includes an audio-video controlling device 12 and a video-processing chip 16. The video-processing chip 16 is coupled to an output end 122 of the audio-video controlling device 12 for receiving an image signal. The audio-video controlling device 12 includes a first microprocessor 111 for controlling operations of the audio-video controlling device 12. The audio-video controlling device 12 further includes an external flash memory 13A for storing program codes. The video-processing chip 16 includes a second microprocessor 17, a flash memory 13B, a scalar 39, a timing controller 38, and a first memory 14.
As shown in FIG. 1, the second microprocessor 17 is externally coupled to the video-processing chip 16. The second microprocessor 17 is an 8051 single-chip for executing some simple program codes. The flash memory 13B is externally coupled to the second microprocessor 17. The flash memory 13B is coupled to the second microprocessor for storing program codes for execution by the second microprocessor 17. The scalar 39 is used for adjusting a size of a received image. The timing controller 38 is coupled to the scalar 39. The first memory 14 is coupled to the scalar 39 for providing memory space to the scalar 39 for image processing. The video-processing chip 16 further includes an output device 19 coupled to the timing controller 38 for outputting signals that are processed by the scalar 39 and the timing controller 38. The video-processing chip 16 further includes an input device 18 coupled between the scalar 39 and the output end 122 of the audio-video controlling device 12. The input device 18 is used for receiving the image signal transmitted by the audio-video controlling device 12. The first memory 14 is a static random access memory (SRAM).
Please refer to FIG. 2 that is a diagram of another audio-video system 20 according to the prior art. The audio-video system 20 includes an audio-video controlling device 12 and a video-processing chip 26. The video-processing chip 26 is coupled to an output end 122 of the audio-video controlling device 12 for receiving an image signal and outputting the processed image signal after image processing. The audio-video controlling device 12 includes a first microprocessor 11 for controlling operations of the audio-video controlling device 12. The audio-video controlling device 12 further includes an external flash memory 13A for storing program codes. The video-processing chip 26 includes a second microprocessor 27, a flash memory 23, a scalar 39, a timing controller 38, and a first memory 14.
As shown in FIG. 2, the second microprocessor 27 is an internal component of the video-processing chip 26. The second microprocessor 27 is an 8051 single-chip for executing some simple program codes. The flash memory 23 is externally coupled to the second microprocessor 27. The flash memory 23 stores program codes for execution by the second microprocessor 27. The scalar 39 is used for adjusting a size of a received image. The timing controller 38 is coupled to the scalar 39. The first memory 14 is coupled to the scalar 39 for providing memory space to the scalar 39 for image processing. The video-processing chip 26 further includes an output device 19 coupled to the timing controller 38 for outputting signals that are processed by the scalar 39 and the timing controller 38. The video-processing chip 26 further includes an input device 18 coupled between the scalar 39 and the output end 122 of the audio-video controlling device 12. The input device 18 is used for receiving the image signal transmitted by the audio-video controlling device 12. The first memory 14 is a static random access memory (SRAM).
In the prior art, no matter whether the second microprocessor is an internal or an external component of the video-processing chip, an external flash memory 13B (as shown in FIG. 1) or flash memory 23 (as shown in FIG. 2) is needed for storing program codes of the second microprocessor 27. This external flash memory increases design cost. Furthermore, even when the audio-video system 10 or the audio-video system 20 gets into the stand-by mode, power is still supplied to the first microprocessor 11 to make sure the whole audio-video system 10 and 20 can work normally when receiving power-on commands. Due to the power not being turned off completely, the audio-video system 10 or the audio-video system 20 still consumes power.